Muffler



- Nov. 5', 1935.

J. W. TATTER MUFFLER I Z3 ZO' INVEN TOR. fa/2n n/ 75 2? ATTORNEY.

Patented Nov. 5, 1935 MUFFLER John W. Tattcr, Detroit, Mich, asslgnor to Continental Motors Corporation, Detroit, Mich, a corporation of Virginia Application December 8, 1930, Serial No. 590,711

10 Claims. (Cl. 137-160) This invention relates to mufllers for use with internal combustion engines.

It is an object of my invention to provide an improved mufiler whereby the sound or noises of 5 the exhaust are muffled with very little back pressure on the engine with consequent minimization of power loss.

It is a further object of my invention to provide a muffler which may be manufactured at very low cost, it being exceedingly important in the automotive field in order to successfully market a muflier to combine features of low back pressure and satisfactory muflling characteristics with low manufacturing cost.

15 Further objects and advantages of my invention will be apparent from the following detailed descrlption of my invention as illustrated in the accompanying drawingin which:

Figure 1 is a longitudinal sectional view through 20 the muffler,

Figure 2 is a sectional view through 2-2 of Figure l, and

Figure 3 is a detail sectional view through 3-3 of Figure 2.

15 In the drawing reference character A represents the customary exhaust pipe conducting the exhaust gases from the engine (not shown) and 'B is the mufller. The muiller preferably is constructed of a plurality of oppositely extending pairsof complementary cup-shaped baflles or partition members l0, l0 and H, II and outer housing members l2, l2. All of these members are preferably tapered outwardly and inwardly from substantially the longitudinal central transverse plane of the muflier to facilitate the die pressing operation in forming these members.

The end walls or partition walls I3, ll, l5, and

Iii of the respective members III, II, ll'h-and Ill divide the muffler into chambers l1, l8, I9, 20,

and 2| there being a central plate or transverse partition member 22 intermediate the walls I4 and I5. One important feature of my invention resides in securing the edges of the cup-shaped partition members I0, I0 II", II and the plate 22 45 together around the circumference of the mufller.

One way in which this may be conveniently done is to "arrange these edges in face contact as shown in Figure 1 with the edge of one of the housing members l2 extended at 23 for secure crimping around the nested edges of the remaining elements.

The successively nested or telescoped baifle members are preferably spaced at their side walls within each other to provide dead air" pockets 24, 25, 26, and 21 for assisting in the muflilng action and also for spacing these members against rattling or transmission of noise to the housing.

The walls I3, I4, 22, I5, and ii are provided with a novel means for producing the muiliing action with exceedingly low back-pressure effect and at 6 very low cost. Thus these walls are die stamped similarly, each having a series of offset tongues 28 preferably arranged in concentric circles about their axes. I have found that these tongues may be conveniently formed substantially circular with 10 their main body portions D lying substantially in a plane parallel with their respective walls, the body portions being connected with the walls by necks 29 thereby forming a plurality of openings 30 in the walls or battles. The tongues 28 are preferably offset on the low-pressure side of each of the baffles or on the side thereof opposite to the source of exhaust gas flow. Further, I have discovered that improved mufi'iing qualities result from arranging the tongues 28 circularly opening in one direction as will best be noted from Figure 2 whereby the exhaust gases in the chambers will be given a circular motion about the muffler axis, this turbulence assisting in breaking up the sound waves and it will be noted that the same circular motion is maintained between successive baflies. In other words I prefer to form the tongues of the several bailles with the same general directional eflect as I have found this to provide excellent results.

While my mufller as thus far described provides for improvements in the art within the stated objects of my invention I contemplate in some instances as a part of my invention to further break up the sound waves as a further improved muiller action by providing at one end of the muffler, preferably adjacent the outlet 33, a secondary baffling device C consisting of a screen or finely perforated plate 3| across the muiller 'housing and in the illustration having a flanged centrally located tubular outlet 32, aligned with and preferably having the same size opening as the main outlet 33 of the mufller. In the space or pocket provided between this baffle C and the housing member I2 I position a quantity of metal wool or chips 34. Thus the sound waves are broken up and dissipated without introducing any material back pressure since the opening 32 does not impose a restriction on the exhaust gases.

By referring to Figure 2 it will be noted that the tongues 28 are located in close proximity to each other whereby a relatively large area of total opening in any wall is provided, this materially minimizing back pressure, while the turbulent swirling action and successive expansion chambers provide for an improved mufliing action.

By reason of my invention I am enabled to obtain improved muflling characteristics including exceptionally low back pressure with a construction substantially one-half to one-third the weight and size of the ordinary mufflers now in general use, such improvements greatly reducing the cost of the muilier.

What I claim as my invention is:

1. In a muflier, a casing, a plurality of spaced walls within the casing, said walls having substantially flat tongues deflected from their respective walls, said tongues of each wall having ofiset portions lying substantially in a plane parallel with the wall associated therewith.

2. In a muflier, a casing comprising oppositely cupped members, a plurality of substantially cupshaped elements within the casing and having openings through which the exhaust gas may flow, and common means securing the edges of said bafliesand casing members, the side walls of said elements being spaced from the casing members and from each other, said elements and members being constructed to provide substantially dead air spaces for exhaust gases ofiset from the normal gas flow.

3. A mufller including a casing, a generally cupshaped member within the casing presenting a perforated wall for exhaust gas passage, said member having non-perforated side walls spaced from and within the casing inner walls whereby to provide chambers offset from the normal gas flow for trapping exhaust gases therein.

4. A muflier including a casing, a series of inner and outer nested cupped elements positioned therein and having openings for exhaust gas passage, the inner elements cooperating with the outer elements to provide chambers oflset from the normal ga's how for trapping exhaust gases therein.

5. In a mufller, a casing, aplurality of substantially uniformly spaced parallel walls within the casing, said walls having substantially flat tongues deflected and onset from their respective walls to provide openings, the offset portions of said tongues of each wall lying substantially in a plane parallel with the wall associated therewith and having sumcient clearance with respect to the edge of the opening whereby to provide passages each having an area at least as great as the area of the opening associated therewith.

6. In a mufller, a casing, a plurality of spaced baille walls disposed within the casing and provided with tongues deflected from said walls whereby to provide openings therethrough, said tongues being ofiset in substantial parallel relation with said associated walls and substantially aligned with said openings for altering the direction oi. gas flow and deflecting said flow through an angle of approximately 90 degrees, said tongues arranged for cooperative action on the inc.

exhaust gas flow to impart a substantial circular movement to the exhaust gases relative to the longitudinal axis of the mufiier.

7. In a muiiler, a casing, a plurality of spaced baflie walls disposed within vlded with tongues deflected from said walls whereby to provide openings therethrough, said tongues being oifset in substantial parallel relation with said associated walls and substantially aligned with said openings for altering the direction of gas flow and deflecting said flow through an angle of approximately 90 degrees, said tongues having heel portions for connecting the tongues with the wall, saidheel portions constructed and cooperating to block the exhaust gas flow in one direction whereby to induce the exhaust gases to flow in a substantial circular movement in the other direction relative to the iongitudinal axis of the muiiler.

8. In a muiller, a casing, a plurality of spaced walls within the casing, said walls having substantially flat circular tongues deflected from their respective walls whereby to provide substantially circular openings in said walls through which exhaust gas may flow within the casing, said tongues being offset from said walls whereby to substantially overlie said openings but having suflicient clearance with respect to the edge of said openings to provide a passage having a cross-sectional area at least as great as the area of the opening.

9. In a mufiler, a casing, a wall extending transversely within the casing and having tongues deflected and ofiset from one face of the 4 wall whereby to provide openings in said wall through which exhaust gas may flow, said tongues being offset from said walls whereby to substantially overlie said openings but having a clearance with respect to the edge 01 said openings less than the diameter of the opening but sufficient to provide a passage having a cross-sectional area at least as great as the area of the opening, said tongues being closely spaced substantially over the full face of said wall.

10. In a muliier, a casing, a wall extending transversely within the casing and having tongues deflected and offset from one face of the wall whereby to provide openings in said wall through which exhaust gas may flow, said tongues being ofl'set from said walls whereby to substantially overlie said openings but having suflicient clearance with respect to the edge of said openings to provide a passage having a cross-sectional area at least as great as the area of the openative-to the longitudinal axis of the muflier. 60

JOHN w. 'm rrER.

the casing and pro- 5 said tongues being closely spaced substan- 3 

